As a semiconductor, zinc oxide (ZnO) has a wide band gap (about 3.4 eV) and has attracted attention because of its potential applications in catalysis, as well as in optoelectronic devices, lasers, field effect transistors, and photovoltaic solar cells. The large-scale adoption of ZnO for these and other industrial applications hinges on obtaining atomic-scale control of surface and interface structure. It is known that the concentration and spatial distribution of point defects (e.g., vacancies, interstitial atoms and/or defect complexes) can strongly influence the manufacture and performance of ZnO and other metal oxides in various applications. For example, ZnO, which is an intrinsically O-deficient metal oxide, may contain large concentrations of oxygen vacancies (Vo) that are introduced during growth or post-growth treatments. Oxygen vacancies are undesirable in many photonic and electronic applications where they act as recombination centers, lowering UV band edge emissions and photocatalytic efficiencies, and contribute to charge compensation, hindering p-type doping in natively n-type oxides. Thus, methods to control oxygen vacancy concentration and distribution could be advantageous.